Polycarbometallane

ABSTRACT

A polymer having a backbone repeat unit that includes at least two metal atoms bonded to each other and only one ethylenically unsaturated functional group wherein the backbone unit preferably has a structure of  
     —C(R 3 )═C(R 3 )—[C(R 3 )(R 4 )] n —[M(R 1 )(R 2 )] a —[C(R 3 )(R 4 )] p — 
     wherein n is 0 to 4; a is at least 2; p is 0 to 4; R 1  and R 2  are each independently selected from hydrogen, halogen, lower alkyl having 4 or fewer carbon atoms, alkenyl having 4 or fewer carbon atoms, or aromatic having one ring; R 3  and R 4  are each independently selected from hydrogen and lower alkyl having 1 to 4 carbon atoms; and M is a metal atom selected from at least one of Sn, Ge, Pb, Hg, Ni, Pd, Pt, Cr, Fe, Co, Cu and Zn.  
     The polymer has at least 20 weight percent metal, preferably at least 50 weight percent metal, based on the weight of the polymer.

[0001] This application claims benefit of U.S. Provisional PatentApplication No. 60/082,963 filed Apr. 24, 1998.

BACKGROUND OF THE INVENTION

[0002] Acyclic diene metathesis (ADMET) polymerization is a steppolycondensation process that has been used to obtain macromolecules. InADMET polymerization, a diene is efficiently condensed to an unsaturatedpolymer by the removal of a small olefin (usually ethylene).

SUMMARY OF THE INVENTION

[0003] There is provided according to the present invention a polymerhaving an ethylenically unsaturated backbone repeat unit that includesat least two metal atoms bonded to each other wherein the backbonerepeat unit includes only one ethylenically unsaturated functional groupor the ethylenically unsaturation is separated by at least one saturatedcarbon atom from the metal-to-metal atoms. Preferably, the polymerincludes a backbone repeat unit having the formula:

—C(R³)═C(R³)—[C(R³)(R⁴)]_(n)—[M(R¹)(R²)]_(a)—[C(R³)(R⁴)]_(p)—

[0004] wherein n is 0 to 4 or 0 to 50, preferably 2 to 50; a is at least2; p is 0 to 4 or 0 to 50, preferably 2 to 50; R¹ and R² are eachindependently selected from hydrogen, halogen, lower alkyl having 4 orfewer carbon atoms, alkenyl having 4 or fewer carbon atoms, or aromatichaving one ring; R³ and R⁴ are each independently selected from hydrogenand lower alkyl having 1 to 4 carbon atoms; and M is a metal atomselected from at least one of Sn, Ge, Pb, Hg, Ni, Pd, Pt, Cr, Fe, Co, Cuand Zn.

[0005] The present invention also provides a method for making anethylenically unsaturated polymer that includes at least two metal atomsbonded to each other comprising reacting a diene monomer that includes apolymetallane segment in the presence of an effective catalyst to obtainthe polymer.

[0006] In particular, the polymers of the invention (III) aresynthesized via acyclic diene metathesis (ADMET) polymerization oftelechelic polymetallane dienes (I) catalyzed by olefin metathesiscatalysts based on organometallic complexes of transition metals such asMo, W, Ta, Ti, Ru (II), Re, Os or Nb.

[0007] There are numerous known metathesis catalysts that might beuseful in the invention. Transition metal carbene catalysts are wellknown. Illustrative metathesis catalyst systems include rheniumcompounds (such as Re₂O₇/Al₂O₃, ReCl₅/Al₂O₃, Re₂O₇/Sn(CH₃)₄, andCH₃ReO₃/Al₂O₃—SiO₂); ruthenium compounds (such as RuCl₃, RuCl₃(hydrate),K₂[RuCl₅—H₂O], [Ru(H₂O)₆](tos)₃ (“tos” signifies tosylate),ruthenium/olefin systems (meaning a solution or dispersion of preformedcomplex between Ru and olefin (monomer) that also includes a β-oxygen inthe presence or absence of a soluble or dispersed polymer where thepolymer can be an oligomer or higher molecular weight polymer preparedby metathesis or other conventional polymerization synthesis), andruthenium carbene complexes as described in detail below); osmiumcompounds (such as OsCl₃, OsCl₃(hydrate) and osmium carbene complexes asdescribed in detail below); molybdenum compounds (such as molybdenumcarbene complexes (such as t-butoxy and hexafluoro-t-butoxy systems),molybdenum pentachloride, molybdenum oxytrichloride, tridodecylammoniummolybdate, methyltricaprylammonium molybdate, tri(tridecyl)ammoniummolybdate, and trioctylammonium molybdate); tungsten compounds (such astungsten carbene complexes (such as t-butoxy and hexafluoro-t-butoxysystems), WCl₆ (typically with a co-catalyst such as SnR₄ (R signifiesalkyl) or PbR₄), tungsten oxytetrachloride, tungsten oxidetridodecylammonium tungstate, methyltricaprylammonium tungstate,tri(tridecyl)ammonium tungstate, trioctylammonium tungstate,WCl₆/CH₃CH₂OH/CH₃CH₂AlCl₂, WO₃/SiO₂/Al₂O₃, WCl₆/2,6-C₆H₅—C₆H₅OH/SnR₄,WCl₆/2,6-Br—C₆H₃OH/SnR₄, WOCl₄/2,6-C₆H₅-C₆H₅OH/SnR₄,WOCl₄/2,6-Br—C₆H₃OH/SnR₄); TiCl₄/aluminum alkyl; NbO_(x)/SiO₂/iso-butylAlCl₂; and MgCl₂. As indicated above, some of these catalysts,particularly tungsten, require the presence of additional activator orinitiator systems such as aluminum, zinc, lead or tin alkyl. Preferredcatalysts are ruthenium compounds, molybdenum compounds and osmiumcompounds.

[0008] Telechelic polymetallane dienes (I) may be synthesized using anysingle or a combination of the following procedures according to theinvention:

[0009] 1) The use of alkenyl metallanes (IV) as chain limiters in thedehydrogenation of metal dihydrides (V) catalyzed by organometalliccomplexes of transition metals such as Zr, Ti, Rh, Pt, Pd, Ni, V, Hf, Scor Ta (VI).

[0010] 2) The use of alkenyl metal halides (VII) as chain limiters inthe Wurtz-type coupling of metal dihalides (VIII) in the presence ofalkali metals such as Li, Na, K, Rb or Cs (IX).

[0011] 3) The sequential alkenylation of polymetallane dihalides (XI) byorganometallic reagents bearing the alkenyl moiety (X) (w and y areindependently any number between 2 and 50).

[0012] 4) The coupling of alkenyl metallanes (IV) with metal diamides(XII).

[0013] In all schemes:

[0014] M is a metal atom selected from at least one of Sn, Ge, Pb, Hg,Ni, Pd, Pt, Cr, Fe, Co, Cu and Zn;

[0015] R₁ and R₂ are independently hydrogen, alkyl or aryl groupscontaining 2 to 50 carbons;

[0016] w and y are independently any number between 2 and 50;

[0017] x and n are independently any number larger than 1;

[0018] X is a halogen atom such as Cl, Br or I;

[0019] E is any electrophile consisting of or containing metals such asLi, Na, K, Cs, Mg, Zn, Cd or Hg.

[0020] In each of these schemes it is possible to use a mixture ofreactants that could have different divalent radicals ( )_(w) and ()_(y) wherein the number of carbon atoms varies. In addition, R₁ and R₂could be bonded to form a cyclic structure to the same metal atom or toadjacent metal atoms.

[0021] Another possible synthetic route to suitable polymetallanemonomers is to use cyclopolymetallane reactants and (1) subject them toUV radiation, (2) two step reaction with CH₂═CH(CH₂)_(n)E and thenCH₂═CH(CH₂)_(n)X (wherein n, E and X are the same as identified above),and (3) reacting with CH₂═CH(CH₂)_(n)M(X)₂(CH₂)_(n)CH═CH₂.

[0022] The polymer should have a high amount of metal, at least about 20weight %, preferably at least about 50 weight %, based on the weight ofthe polymer. Polymers with such a structure should have veryadvantageous electrical and thermal conductivity properties and thus canbe used in conductive films, fibers and solders and photoresists. Inaddition, they should be malleable and easy-to-process since they arevery soluble in organic solvents and should have good melt processingcharacteristics.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The first step in our approach to ADMET polymers containingpolymetallane segments consists of the design and synthesis of suitablediene monomers containing at least one metal-metal σ bond. In order todetermine the compatibility between this functionality and themetathesis catalysts employed in the polymerization, we haveconcentrated our efforts on the preparation of di- and tristannanedienes. The alkenylation of a tri- or distannane dichloride appearedattractive to us since a variety of carbonated segments can beintroduced by the choice of the alkenylating group.

[0024] The synthesis of monomer of formula 2 as shown in Scheme 1 belowinvolves the in situ generation of Bu₂SnHCl, its dehydrogenativecoupling to the distannane dichloride, and the subsequent reaction ofthis dichloride with a nucleophilic alkenyl group, and we have attemptedto reduce this procedure to a one-pot synthesis scheme based on thedifficulties often associated with the purification of tin halides.

[0025] The room temperature disproportionation of equimolar amounts ofBu₂SnCl₂ and Bu₂SnH₂ leading to Bu₂SnHCl has been previously reported inNewmann, W. P.; Pedain, J. Tetrahedron 1964, 36, 2461; (b) Kawakami, T.;Suimoto, T.; Shibata, I.; Baba, A.; Matsuda, H.; Sonoda, N. J. Org.Chem. 60, 2677 (1995). The equilibrium concentrations are reached in ca.10 min at 25° C. Addition of a catalytic amount of dry pyridine or a Pdcomplex to this mixture has also been reported in Newmann et al. tocause the quantitative decomposition of the Bu₂SnHCl to the distannanedichloride. The palladium catalyzed coupling appears to be the mostefficient, and Bu₄SN₂CL₂ solutions are obtained after—oftenvigorous—hydrogen evolution from the precursor Bu₂SnHCl solutions. Thisdisappearance of the signal centered at 44.6 ppm and the simultaneousappearance of a new sharp singlet at 109.0 ppm in the (proton decoupled)¹¹⁹Sn-NMR (1J¹¹⁹Sn−¹¹⁹Sn=2420 Hz), have proven to be very useful in themonitoring of this reaction.

[0026] We have also observed that this methodology can be extended toother polystannane dichlorides, which can be used as precursors fordiene monomers.

[0027] The alkenylation of the distannane dichloride is a facilereaction. Gentle reflux of the dichloride with the Grignard reagentgenerated from 5-bromo-1-pentene affords after workup a mixture of thedienes of formulae 2, 3, and 4 identified by their distinct resonancesin the ¹¹⁹Sn-NMR. However, we have been unable to produce 2 free ofother dienes, and attempts to separate these dienes have also provenunsuccessful. Bu₂SnCl₂ remaining from the incomplete disproportionationreaction accounts for the presence of formula 3, while the coupling ofremaining Bu₂SnH₂ with Bu₂SnHCl in the second step explains the presenceof diene of formula 4. To our surprise, these compounds are quite stablenot only to aqueous workup of the Grignard reaction, but also toadsorbents such as silica gel, which allows their isolation in adequatepurity for ADMET polymerization.

[0028] Upon exposure to the molybdenum catalyst 1, this purified dienemixture produced the ADMET terpolymer of formula 6 in almostquantitative yield. (see Scheme 2 below) Ethylene evolution is veryvigorous during the first 4 h of the reaction, and the viscosity of thereaction mixture increases steadily suggesting polymerization. Afterthis time, ethylene bubbling rate decreases, but continues throughoutthe reaction until viscosity prevents magnetic stirring.Characterization of the crude polymer sample reveals that polymerizationhas indeed taken place, along with the incorporation of the threestannadienes 2, 3 and 4. Both ¹³C and ¹H-NMR of the polymer show theconversion from terminal dienes to internal olefins. New signals at5.5-5.6 ppm (¹H), and at 131.2 and 130.6 ppm (¹³C) account for the newolefin linkages, in both cis and trans isomeric forms. Polymerization isalso evident by the splitting of the ¹¹⁹Sn signals originally present inthe monomer mixture, due to the slightly different magnetic environmentscaused by the olefin linkages.

[0029] Precipitation of the polymers from CDCl₃ or C₆D₆ solutions intomethanol yields the polymers as viscous liquid samples. End groupanalysis based on NMR Spectroscopy suggests an average degree ofpolymerization of 20. (Calculated Mn=11,000 g/mol).

EXAMPLE

[0030] Mo(CHCMe₂Ph)(N-2,6-C₆H₃—Pr₂)(Ocme(CF₃)₂)₂ (catalyst 1) anddi-n-butylstannane were synthesized according to, respectively, Schrock,R. R., Murdzek, J. R., Bazan, G. C., DiMare, M., O'Regan, M. J. Am.Chem. Soc., 112, 3875 (1990) and Imori, T., Lu, V., Cai, H., Tilley, T.D., J. Am. Chem. Soc., 117, 9931 (1995), both incorporated herein byreference. 5-Bromo-1-pentene was purchased from Aldrich Chemical Companyand distilled from CaH₂ immediately before use. Di-n-butyltin dichloridewas purchased from Acros Organics and used as received. Diethyl etherwas distilled from sodium benzophenone ketyl and stored over 4 Åmolecular sieves in an inert atmosphere of argon.

[0031]¹H (300 MHz), ¹³C(75 Mhz), and ¹¹⁹Sn (112 MHz) NMR was performedon a varian VXR-300 MHz superconducting spectrophotometric system usingdeuterobenzene (C₆D₆) as the solvent. ¹H and ¹³C NMR are referenced toan internal 0.05% w/w TMS standard while ¹¹⁹Sn NMR are referenced to aninternal 1% w/w tetramethyltin sample.

[0032] Synthesis of 6,6,7,7-tetrabutyl-6,7-distanna-1,11-dodecadiene(Formula 2)

[0033] In a flame-dried schienk tube, a solution of 1.24 g (4.05 mmol)of Bu₂SnCl₂ in 6 mL of anhydrous diethyl ether was added via syringe toneat Bu₂SnH₂ (1.01 g, 4.26 mmol), and this mixture was stirred under anargon atmosphere for 15 min. Dry pyridine (33 μL, 0.40 mmol) was added,and the mixture was stirred for an additional 4 h. The solvent wasremoved in vacuo and the colorless liquid obtained was weighed andredissolved in 5 mL of diethyl ether to make solution 1.

[0034] A suspension of powdered Mg (0.294 g, 12.11 mmol) in diethylether (6 mL) was kept in a flame-dried three-neck round bottomed flaskunder an argon atmosphere. A solution of freshly distilled5-bromo-1-pentene (1.67 g, 11.18 mmol) in diethyl ether (6 mL) was thenslowly added and this mixture was refluxed for 2 h, time after whichSolution 1 was slowly dropped using an addition funnel. The resultingmixture was refluxed for 20 h, cooled to room temperature and thesupernatant solution was cannula-filtered to a schlenk tube. Addition ofpentane (15 mL) and a second cannula filtration afforded a solutionwhich was washed twice with ice-cold 1 M NH₄CL (2×15 mL), dried overMgSO₄ and filtered through a pad of silica gel. The solvent was removedin vacuo and 1.44 g (64%) of a colorless viscous liquid were obtained.This product (material 5) is a mixture of the three tin containingdienes 6,6-dibutyl-6-stanna-1,10-undecadiene (material 3),6,6,7,7-tetrabutyl-6,7-distanna-1,11-dodecadiene (material 2), and6,6,7,7,8,8-hexabutyl-6,7,8-tristanna-1,12-tridecadiene (material 4) inan undetermined ratio. ¹H NMR: d(ppm)=5.7-5.9 (m, 2 H); 5.0-5.2 (m, 4H); 2.0-2.2 (m, 4 H); 1.6-1.9(m); 1.3-1.6 (m); 1.3-1.1 (m); 0.8-1.1 (m).¹³C NMR: d(ppm)=139.2, 115.5, 39.5, 33.9, 31.7, 30.2, 28.9, 28.5, 27.5,14.5, 11.6-11.3, 10.9-10.6, 9.6-9.3. ¹¹⁹Sn NMR; d(ppm)=−12.4 (3,C—Sn—C), −76.4 (4, C—Sn—Sn —Sn—C), −83.5 (2, C—Sn—Sn—C), −227.3 (4,C—Sn—Sn—Sn—C). Elemental anal. for C₂₆H₅₄Sn₂ (2). Calcd: C(51.70%),H(9.01%). Found: C(51.67%), H(8.76%). HR-MS for C₂₂H₄₅Sn₂ (2)-C₄H₉.Calcd: 547.1579 m/z (Average of two analysis).

[0035] ADMET Polymerization of Mixture of Formula 5.

[0036] In an argon purged dry box, catalyst 1 (5 mg) was weighed andplaced in a 50 mL round bottomed flask adapted with a Rotoflow valve.The monomer mixture (in other words, formula 5) (400 mg) was then addedto the flask which was in turn sealed and taken to a high vacuum schlenkline. Ethylene evolution could be evidenced at room temperature duringthe first 12 h of reaction. After this time, the system was heated to60° C. and the reaction was continued for 24 h. The reaction was stoppedby removal of the heat when magnetic aggitation became impossible orwhen no further bubbling could be evidenced, and the crude viscouspolymeric product of formula 6 was dissolved in C₆D₆ ¹H NMR:d(ppm)=5.5-5.6 (b); 2.0-2.4 (b); 1.6-1.9 (m); 1.3-1.6 (m); 1.3-1.1 (m);0.8-1.1 (m). ¹³C NMR: d(ppm)=131.2, 130.6, 38.7, 38.5, 33.9, 31.7, 30.3,28.9, 28.5, 14.5, 11.6, 112.0, 9.6. ¹¹⁹Sn NMR: d(ppm)=−11.5, −11.6,−11.8, −75.4, −75.5; −82.6, −82.8, −82.9, −83.0; −226.3, −226.4.Elemental anal. for (C₆H₅₀Sn₂)_(n). Calcd: C(50.04%), H(8.75%). Found:C(%), H(%).

[0037] It should be recognized that the polymeric product of formula 6is a distribution of polymer chains wherein a portion of the chains willalso include a backbone unit that has only one metal atom. However, suchpolymer chains also will include backbone units with at least two metalatoms as per the invention.

[0038] Scheme 1.

[0039] Synthesis of monomer 2. Alkylation of residual Bu₂SnCl₂ accountsfor the formation of material 3 (m=2 in formula 5 below). Thepyridine-catalyzed coupling of Bu₂SnH₂ with Bu₂SnHCl in step 3 wouldyield a tristannane dichloride, a precursor to material 4(m=3 in formula5 below).

[0040] Scheme 2.

[0041] ADMET polymerization of the monomer mixture 5 to the terpolymer6.

What is claimed is:
 1. A polymer having a backbone repeat unit thatcomprises at least two metal atoms bonded to each other and only oneethylenically unsaturated functional group.
 2. A polymer according toclaim 1 wherein the metal atoms are selected from at least one of Sn,Ge, Pb, Hg, Ni, Pd, Pt, Cr, Fe, Co, Cu and Zn.
 3. A polymer according toclaim 1 wherein the polymer comprises at least about 20 weight percentmetal, based on the weight of the polymer.
 4. A polymer according toclaim 3 wherein the polymer comprises at least about 50 weight percentmetal, based on the weight of the polymer.
 5. A polymer according toclaim 1 wherein the backbone repeat unit has a structure represented by:—C(R³)═C(R³)—[C(R³)(R⁴)]_(n)—[M(R¹)(R²)]_(a)—[C(R³)(R⁴)]_(p)— wherein nis 0 to 50; a is at least 2; p is 0 to 50; R¹ and R² are eachindependently selected from hydrogen, halogen, lower alkyl having 4 orfewer carbon atoms, alkenyl having 4 or fewer carbon atoms, or aromatichaving one ring; R³ and R⁴ are each independently selected from hydrogenand lower alkyl having 1 to 4 carbon atoms; and M is a metal atomselected from at least one of Sn, Ge, Pb, Hg, Ni, Pd, Pt, Cr, Fe, Co, Cuand Zn.
 6. A polymer according to claim 2 wherein the metal atoms areSn.
 7. A polymer according to claim 5 wherein the metal atoms are Sn. 8.A polymer having a backbone repeat unit that comprises at least twometal atoms bonded to each other and an ethylenically unsaturatedfunctional group separated by at least one saturated carbon atom fromthe metal-to-metal atoms.
 9. A method for making an ethylenicallyunsaturated polymer that includes at least two metal atoms bonded toeach other comprising reacting a diene monomer that includes apolymetallane segment in the presence of an effective catalyst.
 10. Amethod according to claim 9 wherein the diene monomer has a structurerepresented by

wherein M is a metal atom selected from at least one of Sn, Ge, Pb, Hg,Ni, Pd, Pt, Cr, Fe, Co, Cu and Zn; R₁ and R₂ are independently hydrogen,alkyl or aryl groups containing 2 to 50 carbons; w and y areindependently any number between 2 and 50; and x is any number largerthan
 1. 11. A method according to claim 9 wherein the catalyst isselected from a rhenium compound, ruthenium compound, molybdenumcompound, tungsten compound, osmium compound, TiCl₄/aluminum alkyl,NbO_(x)/SiO₂/iso-butyl AlCl₂, or MgCl₂.
 12. A method according to claim10 wherein the catalyst is selected from a rhenium compound, rutheniumcompound, molybdenum compound, tungsten compound, osmium compound,TiCl₄/aluminum alkyl, NbO_(x)/SiO₂/iso-butyl AlCl₂, or MgCl₂.
 13. Amethod according to claim 9 wherein the polymer has a backbone repeatunit having a structure represented by—C(R³)═C(R³)—[C(R³)(R⁴)]_(n)—[M(R¹)(R²)]_(a)—[C(R³)(R⁴)]_(p)—wherein nis 0 to 50; a is at least 2; p is 0 to 50; R¹ and R² are eachindependently selected from hydrogen, halogen, lower alkyl having 4 orfewer carbon atoms, alkenyl having 4 or fewer carbon atoms, or aromatichaving one ring; R³ and R⁴ are each independently selected from hydrogenand lower alkyl having 1 to 4 carbon atoms; and M is a metal atomselected from at least one of Sn, Ge, Pb, Hg, Ni, Pd, Pt, Cr, Fe, Co, Cuand Zn.
 14. A method according to claim 13 wherein the metal atoms areSn.
 15. A method according to claim 10 wherein the metal atoms are Sn.16. A compound having a structure represented by

wherein M is a metal atom selected from at least one of Sn, Ge, Pb, Hg,Ni, Pd, Pt, Cr, Fe, Co, Cu and Zn; R₁ and R₂ are independently hydrogen,alkyl or aryl groups containing 2 to 50 carbons; w and y areindependently any number between 2 and 50; and x is any number largerthan
 1. 17. A polymer having at least one backbone repeat unit thatcomprises at least two metal atoms bonded to each other and only oneethylenically unsaturated functional group.
 18. A polymer according toclaim 5 wherein n and p are each independently 0 to
 50. 19. A polymeraccording to claim 5 wherein n and p are each independently 0 to 4.